Fuel feed system for spray type oil burners



Oct. 18, 1949. WITHERELL 2,484,920

FUEL FEED SYSTEM FOR SPRAY TYPE OIL BURNERS Filed Oct. 7, 1946 2 Sheets-Sheet l IN VEN TOR.

Oct. 18, 1949. R. R. WITHERELL 2,484,920

FUEL FEED SYSTEM FOR SPRAY TYPE OIL BURNERS Filed Oct. 7, 1946 2 Sheets-Sheet 2 INVENTOR.

i le/2 7f II/z ZZe/zZZ E-E- w Patented Oct. 18, 1949 FUEL FEED SYSTEM FOR SPRAY TYPE OIL BURNERS Robert R. Withereil, Bloomington, Ill., assignor to Eureka Williams Corporation, Detroit, Mich., a

corporation of Michigan Application October 7, 1946, Serial No. 701,641

7 Claims.

This invention relates to oil burners and has particular reference to oil burners of the low pressure type.

A principal object of the invention is to provide an oil burner of the low pressure type which is more simple in construction and more eflicient in operation than burners of this type as heretofore made.

Another object of the invention is to provide in an oil burner a new and improved system for supplying oil and air under pressure to a nozzle which is constructed to mix such oil and air and to discharge the mixture in the form of an oil fog.

Another object of the invention is to provide in an oil burner a new and improved form of shutoff and pressure regulating valve.

Other and further objects of the invention will be apparent from the following description and will be understood by reference to the accompanying drawings, of which there are two sheets, which, by way of illustration, show a preferred embodiment and the principles thereof and what I now consider to be the best mode in which I have contemplated applying those principles. Other embodiments of the invention embodying the same or equivalent principles may be used and structural changes may be made as desired by those skilled in the art without departing from the present invention and the purview of the appended claims. I also contemplate that of the several diflerent features of my invention, certain ones thereof may be advantageously employed in some applications separate and apart from the remainder of the features.

In the drawings Fig.- 1 is a schematic view of an oil burner embodying the invention;

Fig. 2 is a side elevational view of a pump unit forming part of an oil burner embodying the invention; and

Fig. 3 is a sectional view taken along the line 3-3 of Fig. 2, looking in the direction of the arrows.

Referring now to Fig. 1, the oil burner embodying the invention comprises in general an air tube It, a nozzle l2 arranged in the end of the air tube and adapted to discharge an oil fog into the air flowing through said tube past said nozzle, means in the form of a motor driven fan l4 for eflecting the flow of air through said tube l0, an oil metering pump 16, a suction pump I8, pressure regulating and shutofl valves indicated generally at 20, an air pump 22 and a mufiier 24.

The nozzle l2 may be of the construction disclosed in Williams Patent No. 1,934,755, issued November 14, 1933, for Burner assembly," and includes an outlet 30 through which a mixture of air and oil is discharged in the form of an oil fog into the air flowing past the nozzle and through the tube Ill. The nozzle is supplied with air under pressure from the air pump by means of an air pipe or line 32 and with oil under pressure from the metering pump l6 by means of an oil line or pipe 34. The nozzle includes several air passageways 36 into which jets of oil are delivered by the oil passages 38, the arrangement being such that the oil and air are mixed and delivered in the form of an oil fog from the nozzle through the outlet 30 thereof. For further details respecting this type of nozzle, reference may be had to the aforesaid Williams patent.

The air pump 22 comprises a rotary vane type pump, including a rotor 40 and a plurality of radial vanes 42 carried by the rotor and arranged in a pump chamber 44. Air is supplied to the pump inlet 45 through an air line 48 and the mufiier 24, while the air line 32 communicates with the outlet 50 of the pump. In order to determine the discharge pressure of the pump 22, a bypass 52 is arranged between the outlet and inlet thereof and an air pressure regulating valve 54 is associated with such bypass whereby the discharge pressure of the pump 22 may be determined. Such valve 54 may be a simple needle valve providing a reduction in pressure by allowing air under pressure to return to the suction side of the pump 22. The pump 22 is adapted to deliver primary air to the nozzle within a range of one to five pounds per square inch.

Oil from a suitable reservoir is supplied by an oil line 56 to a filter 58 and from such filter the oil is conducted by means of an oil line 60 and 62 to the gear pump l8. Such gear pump forms a suction pump for withdrawing oil from the reservoir and for supplyin it under pressure through the oil line 64 to the intake of the oil metering pump It. The oil metering pump I6 is adapted to meter predetermined quantities of oil under pressure to the nozzle I2 through the oil line 34.

The metering pump it and gear pump l8 may be of the type illustrated in my copending application, Serial No. 706,139, filed October 28, 1946, for Oil burners. The metering pump l6 may comprise an oscillating cylinder member 66 in which a cylinder is provided and a piston 58 operatively connected to an adjustable eccentric 10. Upon the intake stroke of the pump, oil flows through the line 64 into the cylinder of the metering pump and during the discharge stroke of the pump, the oil flows under pressure from the cylinder into the line 94 to the nozzle I2.

The lines 66 and 34 terminate in oil inlet and outlet ports for the metering pump and the cylinder member 65 is provided with a duct I2 communicating with the cylinder and which is alternately brought into registry with the inlet port I4 and the outlet port I6 upon oscillation of the member 66. The construction of the metering pump I6 is such that the stroke of the piston 60 thereof may be adjusted in order to vary the amount of fuel supplied to the nozzle I2. A surge chamber diagrammatically illustrated at 80 may communicate with the fuel line 34 in order to reduce or eliminate the pulsations therein.

The shut off and pressure regulating valves indicated generally at 20 comprise a shut off valve member 90 and a pressure regulating valve member 92. The valve member 90 comprises a poppet type of valve arranged to seat on a valve seat 94 which is formed around a communication 96 between the oil lines 60 and B2. A coil spring 98 is arranged to bias the valve member 90 to its seat. The pressure regulating valve member 92 is arranged in a bore I which forms part of a bypass between the discharge and intake sides of the pump I8, such bypass further including an oil line I02 between the oil line 64 and the bore I00 and an oil line I04 between the bore I00 and the fuel supply line 56.

In the position shown in Fig. 1, pressure regulating valve 92 which is reciprocable in the bore I00 is closing oil the communication of the line I00 with the bore I00. A stem I06 movable with the valve member 90 depends into the bore I00 and is arranged to obstruct the upward path of movement of the valve member 92. The bore I00 at its top is open to the oil line 62 and the communication 96. On its underside, thepressure regulating valve 92 is exposed to the pressure of the oil discharged by the pump I8.

After the system has once been started, the oil lines, etc. are normally full of oil and a small portion of oil will always remain in the sump under the stem I06 of the fuel shut off valve. Upon rotation of the gears of the suction pump I8, the oil on the discharge side of the pump in the line I02 and on the underside of the valve 92 will lift such valve, which in turn, will engage the valve stem I06 and lift the same, thereby to unseat the valve 90 from its seat, thereby opening the shut off valve. The spring 98 will oppose opening movement of the valve and upward movement of the valve member 92. However, as the pump I 8 is arranged to deliver oil in excess of that handled by the metering pump I6, the valve 92 will move upwardly to uncover the oil line I04 and permit the excess oil to be returned to the oil line 56. As soon as the pump I 0 ceases operation, the valve 90 will automatically shut off the communication between such pump and the fuel supply.

A manually operated plunger H0 is arranged below the valve member 92 so that the pressure regulating valve 92 and the shut off valve 90 may be manually operated for priming purposes. An 0 ring seal I I2 may be arranged around the stem IIII so as to seal the same. The spring 98 and valve member 90 are arranged in the valve chamber I I6 formed in the valve block I I8. The details of construction of the filter 58, shut ofi valve and pressure regulating valve are illustrated more completely in Fig. 3.

The block I I8 comprises a part of the assembly as shown in Fig. 2 which further includes the metering pump I6, the gear pump I8 and the air pump 22. Such pumps are arranged to be driven from the shaft I20 at the same speed, such shaft being connected to an electric motor. The oil metering pump It includes an adjusting member I22 by means of which the stroke of the piston 68 may be adjusted. The oil metering pump is arranged to deliver oil to the nozzle I2 at the same pressure as that at which air is supplied to the nozzle by the pump 22. Thechamber H6 in the block I I8 also houses the pressure regulating valve 92. The ends of such chamber are closed by means of caps I30. The filter 58 likewise is arranged in a chamber in the block II8 closed by caps I32.

The motor driven blower I4 which supplies air to the tube I0 is diagrammatically illustrated and is arranged to supply a stream of secondary air to the nozzle of the burner and into which the oil fog is dispersed so as to provide a combustible mixture which may be ignited by means of the electrodes I40. The mixture is adapted to burn outside of the tube I0, the end of which may be provided with bafiles I42 so as to impart a rotary motion to the air as it leaves the end of the tube I0.

While I have illustrated and described a preferred embodiment of my invention, it is understood that this is capable of modification and I,

therefore, do not wish to be limited to the precise details set forth, but desire to avail myself of such changes and alterations as fall within the nurview of the following claims.

I claim:

1. An oil burner comprising an air pump, an oil and air mixing nozzle, said air pump being connected with said nozzle for supplying air under pressure thereto, means for flowing air past said nozzle, an oil supply pump, an oil supply line for conducting oil to the suction side of said oil pump, a valve in said line arranged to shut off the flow of oil through said line to said oil pump, an oil metering pump, a line for conducting oil under pressure, discharged bysaid oil supply pump to the intake of said 01 meterng pump, a by-pass around said supply pump and between said oil lines, said by-pass communicating with said first mentioned oil line ahead of said valve, a valve member in said by-pass normally closing said by-pass when said supply pump is not operating, said valve member being moveable to open position in response to the pressure of oil in said by-pass and being engageable with said valve for opening the same, an oil line arranged to conduct oil discharged by said oil metering pump to said nozzle for supplying oil under pressure thereto, said nozzle being constructed so as to mix the oil and air supplied thereto and to discharge such mixture in the form of an oil fog into the air flowing past said nozzle. v

2. An oil burner comprising an air pump, an oil and air mixing nozzle, said air pump being connected with said nozzle for supplying air under pressure thereto, means for flowing air past said nozzle, an oil supply pump, an oil supply line for conducting oil to the suction side of said oil pump, an oil metering pump, a line for conducting oil under pressure, discharged by said oil supply pump to the intake of said oil metering pump, a by-pass around said supply pump and between said oil lines, a valve member in said by-pass normally closing said by-pass when said supply pump is not operating, said valve member being moveable to open said by-pass in response to the pressure of oil in said by-pass, an 011 line arranged to conduct oil discharged by said oil metering pump to said nozzle for supplying oil under pressure thereto, said nozzle being constructed so as to mix the oil and air supplied thereto and to discharge such mixture in the form of an oil fog into the air flowing past said nozzle.

3. An oil burner comprising an air pump, an oil and air mixing nozzle, an air line connecting said air pump with said nozzle for supplying air under pressure thereto, means for flowng air past said nozzle, an oil supply pump, an oil supply line for conducting oil to the suction side of said oil pump, an oil metering pump, a line for conducting oil under pressure, discharged by said oil supply pump to the intake of said oil metering pump,

a by-pass around said supply pump and between said oil lines, a pressure regulating valve in said by-pass for controlling the flow of oil therethrough, an oil line independent of said air line arranged to conduct oil discharged by said oil metering pump to said nozzle for supplying oil under pressure thereto, said nozzle being constructed so as to mix the oil and air supplied thereto and to discharge such mixture in the form of an oil fog into the air flowing past said nozzle, and a shut off valve in one of said oil lines constructed and arranged to be opened by pressure of oil in said oil line between said oil supply pump and the intake of said oil metering pump.

4. An oil burner comprising an air pump, an oil and air mixing nozzle, said air pump being connected with said nozzle for supplying air under pressure thereto, means for flowing air past said nozzle. an oil supply pump, an oil supply line for conducting oil to the intake of said oil pump, a valve in said line arranged to shut off the flow of oil through said line to said oil pump, an oil metering pump, a line for conducting oil discharged by said oil supply pump to the intake of said oil metering pump, a passage around said supply pump and between said oil lines, a member in said passage moveable in response to the pressure of oil discharged by said oil supply pump and being engageable with said valve for opening the same, an oil line for conducting the oil discharged by said oil metering pump directly to said nozzle for supplying oil under pressure thereto. said nozzle being constructed so as to mix the oil and air supplied thereto and to discharge such mixture in the form of an oil fog into the air flowing past said nozzle.

5. An oilburner comprising an oil and air mixing nozzle, an air pump connected with said nozzle for supplying air under pressure thereto, means for flowing air past said nozzle, an oil supply pump an oil line for conducting oil to the suction side of said oil pump, an oil metering pump, a line for conducting oil under pressure discharged by said oil supply pump to the intake of said oil me- .tering pump, a by-pass around said supply pump and between said oil lines, a valve member in said by-pass operable for regulating the flow of oil therethrough and around said oil supply pump during such pump operation so as to by-pass to the suction side of said oil supply pump, oil discharged thereby in excess of the requirements of said oil metering pump, an oil line arranged to conduct oil discharged by said oil metering pump to said nozzle for supplying oil under pressure thereto, said nozzle being constructed so as to mix the oil and air supplied thereto and to discharge such mixture in the form of an oil fOg into the air flowing past said nozzle, a valve in one of said oil lines constructed and arranged to shut off the flow of oil therethrough when said oil pumps are not operating, said valve being arranged so as to be opened by pressure of oil discharged from said oil supply pump.

6. An oil burner comprising an oil and air mixing nozzle, an air pump being connected with said nozzle for supplying air under pressure thereto, means for flowing air past saidnozzle, an oil supply pump, an oil line for conducting oil to the suction side of said oil pump, an oil metering pump, a line for conducting oil under pressure discharged by said oil supply pump to the intake of said oil metering pump, a Dy-pass around said supply pump and between said oil lines, a valve member in said by-pass operable for regulating the flow of oil therethrough and around said oil supply pump during such pump operation so as to by-pass to the suction side of said oil supply pump oil discharged thereby in excess of the re quirements of said oil metering pump, an oil line arranged to conduct oil discharged by said all metering pump to said nozzle for supplying oil under pressure thereto, common means for operating said pumps, said nozzle being constructed so as to mix the oil and air supplied thereto and to discharge such mixture in the form of an oil fog into the air flowin past said nozzle, a valve in one of said oil lines constructed and arranged to shut off the flow of oil therethrough when said oil pumps are not operating, said valve being arranged so as to be opened and maintained open by pressure of oil discharged from said oil supply pump.

7. An oil burner comprising an oil and air mixing nozzle, an air pump connected with said nozzle for supplying air under pressure thereto, means for flowing air past said nozzle, an oil supply pump, an oil line for conducting oil to the suction side of said oil pump, an oil metering pump, a line for conducting oil under pressure discharged by said oil supply pump to the intake of said oil metering pump, a by-pass around said supply pump and between said oil lines, a valve member in said by-pass operable for regulating the flow of oil therethrough and around said oil supply pump during such pump operation so as to by-pass to the suction side of said oil supply pump oil discharged thereby in excess of the requirements of said oil metering pump, an oil line arranged to conduct oil discharged by said oil metering pump to said nozzle for supplying oil under pressure thereto, said nozzle being constructed so as to mix the oil and air supplied thereto and to discharge such mixture in the form of an oil fog into the air flowing past said nozzle, a valve in one of said oil lines constructed and arranged to shut off the flow of oil therethrough when said 0i1 pumps are not operating, said valve being arranged so as to be opened by said valve member upon movement thereof in response to pressure of oil discharged from said oil supply pump.

ROBERT R. WITHERELL.

REFERENCES CITED The following references are of record in the flle of this patent:

UNITED STATES PATENTS Number Name Date 1,591,976 Holden et a1 July 13, 1926 1,934,755 Williams Nov. 14, 1933 1958.410 Schaeren May 15, 1934 2,028,807 Reiboldt Jan. 28, 1936 2,378,379 Behrens June 19, 1945 

